In vivo evaluation of the influence of various drug carriers with incorporated hyperaemic drug to changes in the partial pressure of oxygen in rat oral mucosa using EPR oximetry.

摘要

The purpose of this study was to select the best drug carrier among the different types of liposomes for the topical treatment of oral mucosa lesions. A hyperaemic drug, benzyl nicotinate (BN), which increases perfusion and consequently tissue oxygenation, was used as the active ingredient. Electron paramagnetic resonance (EPR) oximetry using a lithium phthalocyanine paramagnetic probe was used in vivo to measure the effects of the benzyl nicotinate which had been incorporated into the liposomes of varying lamellarity and composition. The liposomes were made from either hydrogenated or non-hydrogenated soya lecithin. We used polymethyl methacrylate (PMMA) as the ointment due to its better mucoadhesive properties. EPR oximetry was used to measure the partial pressure of oxygen (pO2) in the oral mucosa before and after the application of the liposomes. It was found that the most pronounced changes of pO2 in oral mucosa and also the longest action of the drug occurred after the topical application of BN in multilamellar liposomes made from hydrogenated soya lecithin (p<0.0001). Therefore, these liposomes proved to be most appropriate for local drug delivery to oral mucosa..